A new method for studying the genetic control of specific mitochondrial proteins in Paramecium aurelia

Summary Mitochondria from one syngen (or sub-species) of Paramecium aurelia have been introducted into a different syngen by preparing erythromycin-resistant mitochondria from syngen 1 and micro-injecting them into erythromycin-sensitive syngen 7 cells. The recipient sensitive cells were then placed in erythromycin to inhibit the replication of the sensitive mitochondria. Such selected clones contain a syngen 7 nucleus but a mitochondrial genome which is derived from syngen 1 erythromycin-resistant mitochondria.Using this method it has been shown that the mitochondrial enzyme fumarase is not coded by the mitochondrial genome, and by implication, is coded by the nuclear genome. The use of this technique as a method for determining if specific mitochondrial proteins are controlled by nuclear or mitochondrial genes is discussed.